The far right Radical Party of Oleg Lyashko has left the ruling coalition in the Ukrainian parliament after a vote on constitutional amendments aimed at decentralizing the country took place, having been required by the Minsk agreements.

“We do not see the possibility of staying in the coalition. We are joining the opposition,” Oleg Lyashko, leader of the party which has 21 of 450 seats in the Parliament, said on Tuesday as cited by TASS news agency.

Lyashko also strongly criticized president Poroshenko saying that he is not better – maybe even worse – than the previous president Yanukovich, who was ousted in a coup in February 2014.

From Lyashko’s point of view the vote on the constitutional amendments aimed at granting more powers to the regions is the result of a “conspiracy between the former Party of Regions and oligarchs” who have built an “anti-Ukrainian coalition”.

Lyashko also insisted on a nationwide referendum to decide on whether rebellious eastern Ukrainian regions should be granted a special status, and called for a thorough investigation of the clashes which took place near the Ukrainian parliament on Monday.

Lyashko's decision to leave the coalition has led to the resignation of Ukraine's vice prime minister, Valeriy Voshchevskiy, who is a member of the Radical Party.

“Leaving the coalition is the Radical Party's joint decision, reached unanimously. Everyone agreed with this decision, and, as a result, the Radical Party cannot be represented in the government. This means for me personally that I resign,” said Voshchevskiy, TASS news agency reported.

Oleg Lyashko is a far-right politician who has been involved in a number of violent incidents over the past two years. In one of his videos posted online Lyashko interrogated one of the leaders of the self-proclaimed Donetsk People’s Republic, Igor Khakmizyanov, half-naked and tied up, after he had been captured by one of Kiev’s military units.

Lyashko was convicted of large-scale embezzlement and abuse of power and sentenced to six years in jail in 1994, but was amnestied a year later.

Several days ago a new criminal case was reportedly opened against Oleg Lyashko and his fellow party member Igor Mosiychuk. Both are accused of organizing a criminal group, kidnappings and torture.

On Monday the majority of Ukrainian MPs voted in favor of the amendments to the constitution which would provide for the decentralization of the country. About 3,000 radicals gathered in front of parliament during the vote. The rally spilled over into violent clashes with the police, resulting in the deaths of at least two members of the country's National Guard and 130 people injured.

Granting more powers to the eastern Ukrainian regions is one of the key provisions of the Minsk agreements, in accordance with the roadmap to stability in Ukraine, which was agreed internationally in February this year.